Pleiotropic regulation of mitochondrial translational factors in governing proliferation, apoptosis and metastasis during cancer progression

Abstract

Mitochondrial translation relies on the coordinated activity of mitoribosomes, mitochondrial ribosome proteins, mitochondria-specific transfer RNAs, and dedicated translation factors, including mitochondrial initiation factor 2/3, mitochondrial elongation factor Tu, mitochondrial elongation factor Ts, mitochondrial elongation factor G1/G2, mitochondrial elongation factor 4, mitochondrial ribosome recycling factor, and mitochondrial release factor 1A. These components collectively drive the synthesis of 13 essential polypeptides encoded by mitochondrial DNA, all constituting subunits of the oxidative phosphorylation complexes. Although mitochondrial metabolism is increasingly recognized as a key player in cancer, the specific contribution of mitochondrial translation to cancer progression remains poorly explored. This gap in knowledge limits our understanding of how mitochondrial dysfunction contributes to tumor initiation, progression, and therapy resistance. Herein, in this review, we highlight how dysregulation of mitochondrial translation factors can influence major cancer hallmarks such as sustained proliferative signaling, resistance to apoptosis, and increased invasion and metastasis. In addition, we discuss the known molecular mechanisms that link defects in mitochondrial translation to oncogenic features. We also consolidate current insights into the mitochondrial translation machinery and discuss recent evidence of its role in cancer, aiming to emphasize mitochondrial translation as a contributor to malignancy and a potential therapeutic target.

Key Words: Mitochondrial translation; Hallmark; Cancer; Mitochondrial translation factors; Mitochondrial ribosomal proteins

Core Tip: Mitochondrial translation machinery synthesizes 13 essential oxidative phosphorylation proteins through specialized ribosomes, translation factors and mitochondrial ribosomal proteins. This review demonstrates how the dysregulation of these components drives key cancer hallmarks, including sustained proliferation through enhanced adenosine triphosphate production, resistance to cell death via disrupted reactive oxygen species/AMP-activated protein kinase signaling, and invasion and metastasis through epithelial-mesenchymal transition and cytoskeletal remodeling. Preclinical evidence supports therapeutic targeting using agents like tigecycline and nanobodies, showing significant anti-tumor effects across multiple cancer types. Translation factors emerge as both prognostic biomarkers and actionable therapeutic targets, positioning mitochondrial translation as a promising vulnerability for metabolism-based cancer treatments with clinical translation potential.

INTRODUCTION

Mitochondria are dynamic organelles essential for various cellular processes, including adenosine triphosphate (ATP) synthesis via oxidative phosphorylation (OXPHOS), metabolic regulation, and cellular signaling pathways[1]. The precise regulation of mitochondrial activities is essential for maintaining cellular homeostasis and adaptive responses to environmental stimuli[1]. Disruptions in mitochondrial dynamics and bioenergetics have been linked to a range of pathologies, notably in oncogenesis, where altered mitochondrial metabolism can influence tumor progression and response to therapies[2,3].

Focusing on mitochondrial translation has become increasingly important due to the metabolic dependency of cancer cells and the distinct structural differences in their machinery compared to cytoplasmic translation[4,5]. Mitochondria harbor a unique protein synthesis system essential for energy production and cellular homeostasis, as mitochondrial DNA (mtDNA) encodes essential components of the OXPHOS system[5]. Mitochondrial translation is carried out by ribosomes known as mitoribosomes, translation factors like mitochondrial initiation factor (MTIF) 2, mitochondrial elongation factor Tu (TUFM), mitochondrial elongation factor G1 (GFM1), mitochondrial ribosome recycling factor (MRRF), transfer RNAs (tRNAs) and mitochondrial ribosomal proteins (MRPs)[4]. The most fundamental challenge in mitochondrial targeting lies in the organelle’s complex double-membrane structure. Therapeutic agents must traverse multiple cellular barriers like plasma membrane permeability, cytosolic barriers, endolysosomal entrapment before reaching to mitochondria. Mitochondrial diseases are phenotypically and genetically heterogeneous, which creates several challenges in treatment[6,7]. Nonetheless, targeting mitochondrial translation offers unique therapeutic advantages through selective vulnerability of mitoribosomes to specific antibiotics while sparing cytoplasmic ribosomes, structural uniqueness with distinct ribosomal RNA (rRNA)/protein composition providing specific drug binding sites, and evolutionary divergence creating multiple distinct molecular targets. The specialized function of synthesizing only 13 essential OXPHOS proteins enables metabolic intervention strategies, while context-specific inhibition mechanisms allow sequence-selective targeting approaches with reduced off-target effects and improved therapeutic specificity.

Emerging studies have explored the targeting of mitochondrial translation in various cancers. For instance, Myc-driven lymphomas exhibit heightened sensitivity to mitochondrial translation inhibitors like tigecycline, with preclinical models showing prolonged survival[8]. Elevated expression of TUFM is associated with proliferation and migration capacity of gastrointestinal stromal tumors (GISTs) cells[9]. Knockdown of mitochondrial elongation factor 4 (mtEF4) in lung cancer cells reduces basal oxygen consumption rate and increases basal extracellular acidification rates, linking mitochondrial translation to bioenergetic shifts[10]. In estrogen receptor/progesterone receptor (+) breast tumors, there is a significant correlation between altered expression of MRPs and OXPHOS subunits (Table 1)[11]. Certain MRPs have been recognized as potential oncogenes, like MRP large subunit (MRPL) 11, which may act as biomarkers for the progression and metastatic potential of human head and neck squamous cell carcinoma (HNSCC; Table 1)[12,13]. Likewise, elevated levels of MRP small subunit (MRPS) 23 and MRPL27 promote the proliferation of hepatocellular carcinoma (HCC) and cholangiocarcinoma, respectively and are associated with poor survival rates (Table 1)[14,15].

Table 1 Role of dysregulated mitochondrial translation factors in various cancers.

No.	Cancer	Samples				Translation factor involved	Expression	Mechanism of action	Techniques and assays performed	Application in clinical settings	Ref.
		Cell lines	Clinical samples		Animal models
			Control	Patients
1	HNSCC	HaCaT, HN8, HN12, HN13, HN22	NA	n = 6	NA	MRPL11	Downregulated	Impaired mitochondrial translation due to reduced expression of MRPL11 leads to defective synthesis of mitochondrial-encoded proteins (e.g., COII), which in turn impairs OXPHOS. This defect potentially forces a metabolic shift to aerobic glycolysis (Warburg effect), aiding tumor survival and progression, particularly in metastatic sites	Western blotting, qRT-PCR, wound healing assays	MRPL11 downregulation and mitochondrial translation defects may serve as biomarkers for HNSCC progression and metastatic potential	[13]
2	LC and BC	A549, CCL64, NCI-H446, MCF7, MDA-MB-453, MDAMB-231 and 293T	NA	NA	Nude mouse (n = 5)	TUFM	Upregulated	Loss of TUFM induces EMT and metastasis of lung cancer cells via a mechanism involving activation of the AMPK/GSK3β/β-catenin pathway	Cell migration assays, colony formation, cell cycle analysis, BrdU cell proliferation assay; qRT-PCR; western blotting and immunofluorescent staining, lentiviral transduction, analysis of glycolytic activity, measurement of cellular ROS; nuclear extraction; ATP and NAD1/NADH quantification; measurement of enzyme activity in complex I and complex IV, tissue microarray; IHC	NA	[31]
3	HNSCC	PCI-13, UDSCC2, SCC90, UMSCC22b	NA	n = 23	NA	TUFM	Upregulated	TUFM, together with NLRX1, forms a mitochondrial complex that: (1) Promotes beclin-1 polyubiquitination; (2) Disrupts beclin-1 and rubicon interaction (which otherwise suppresses autophagy); and (3) Promotes ER stress signaling (eIF2α phosphorylation, UPR activation). This autophagy induction counteracts the anti-proliferative effects of EGFR inhibitors	RNAi-based protein expression knockdown and plasmid transfection, Western blots and co-immunoprecipitation; laser confocal imaging and colocalization analysis, TMA analysis	Increased p62 expression post-treatment is associated with poor response to cetuximab, suggesting: (1) p62 could serve as a predictive biomarker for cetuximab response; and (2) Targeting autophagy (e.g., TUFM, Beclin-1 interaction) may improve therapeutic response	[34]
4	Myc-driven lymphoma	Eμ-myc lymphoma cells (murine), Ba/F3 cells, R26-MERT2 MMECs, Raji, Ramos, Namalwa, Daudi (human Burkitt’s lymphoma)	NA	NA	C57BL/6J mice	MRPS5, MRPS27, PTCD3	Upregulated	Activation of c-Myc sensitizes tumor cells to mitochondrial translation inhibition	shRNA library screen, immunoblot analysis; RNA extraction, qRT-PCR, cell growth and apoptosis assay; OCR, ATP and mitochondrial membrane potential measurement; histology and IHC staining	The identification of Myc as a determinant of tigecycline sensitivity provides a new potential indicator for the re-purposing of this antibiotic in the clinical setting	[8]
5	DLBCLs	DHL4, DHL6, Ly1, Toledo, Pfeiffer, K422, Ly4, DHL2, U2932, HBL-1	NA	Not given	NA	MRPL12, GFM1 MRPS7, MRPS25, MRPS22, MRPS5, MRPS9, YARS2 DARS2, MRPL46, TUFM, MRPS16, PUS1	Upregulated	NA	Mitochondria isolation; iTRAQ labeling; deep sequencing; mass spectrometry, RNAi; Tigecycline treatment; viability and proliferation assays; biochemical measurement of respiratory chain enzyme activity; analysis of mitochondrial respiratory chain super complexes; measurement of mitochondrial SRC; determination of mitochondrial superoxide content, analysis of primary DLBCL samples	Tigecycline selectively inhibits mtDNA-encoded protein translation	[50]
6	Colorectal carcinoma	NA	n = 261	n = 261	NA	TUFM	Upregulated	This association indicated that upregulated TUFM expression during the colorectal normal–adenoma–carcinoma sequence may contribute to the transformation from normal mucosa to carcinoma through adenoma	IHC	NA	[35]
7	RCC	786-0 and A-498	NA	NA	BALB/C mice	TUFM	Upregulated	Knockdown of TUFM along with tigecycline treatment in RCC cells leads to reduced cell growth and survival as a consequence of the suppression of essential growth/ survival signaling pathway PI3K/AKT/mTOR	Measurement of cell proliferation; apoptosis and colony formation; western blotting; qRT-PCR; mitochondrial complex activities; measurement of mitochondrial respiration; RNAi of human EF-Tu expression; RCC cancer xenograft mouse model	NA	[36]
8	HCC	MHCC97-H, SMMC-7721	n = 50, TCGA	n = 50, TCGA	Nude mice (BALB/C)	MRPS23	Upregulated	MRPS23 overexpression contributes to: (1) Enhanced proliferation of HCC cells in vitro and in vivo; (2) Associated with larger tumor size, higher TNM stage, and shorter survival; (3) May promote proliferation through enhanced oxidative phosphorylation and changes in tumor metabolism; and (4) No significant role found in migration/invasion	HCC tissue microarray and IHC analysis; lentiviral infection; RNA extraction; qRT-PCR; western blotting; immunofluorescence; cell proliferation and colony formation assay; cell migration and invasion assays	High MRPS23 expression contributes to HCC proliferation and indicates poor survival outcomes	[14]
9	Breast cancer	MCF10A, MCF7, MDA-MB-231, MDA-MB-435, MDA-MB-468	NA	n = 366	NA	NA	Upregulated	RK-33 inhibits DDX3 blocks mitochondrial translation. Consequences: Mitochondrial-encoded proteins; OXPHOS capacity and ATP production; reactive oxygen species (ROS); apoptosis and autophagy; radiation-induced DNA repair; leads to a bioenergetic catastrophe in cancer cells	Cell viability assays; immunoblotting; proteomics; immunofluorescence; mitochondrial translation assay; measurements of oxygen consumption; ATP quantification; mitotracker flow cytometry; measurement of reactive oxygen species; electron microscopy; colony forming assay	RK-33 serves as a radiosensitizer in breast cancer and is a potent inhibitor of mitochondrial translation, which consequently diminishes the mitochondrial OXPHOS capacity and elevates ROS production in cancer cells	[54]
10	Colorectal cancer	RKO (colon cancer), Hela (cervical cancer), SK-Hep-1 (liver cancer), ZR-75-30 (BC), CRL-5803 (LC), MGC-803 (gastric cancer)	NA	n = 60	Nude mice	MRPL33	Upregulated	Role played by MRPL33-L (an isoform of MRPL33) proteins in colon cancer cell growth, cancer development and repress cancer cell apoptosis	Cell growth and colony-survival assay, RNA isolation; qRT-PCR; western blotting and immunoprecipitation, Generation of recombinant lentivirus and MRPL33 minigenes; mitochondria staining; ROS assay; ATP detection and analysis of apoptosis; RNA-seq	NA	[46]
11	LC; cervical cancer; esophageal cancer; bladder cancer	HeLa, H1299, A549, MDA-MB-231, HepG2, SK-MES-1, H460, K562, PC3, HFF (control), 16HBE, PASMC	Not given	Not given	Nude mice	mtEF4	Upregulated	Low mtEF4 increases mt-translation but decreases translational fidelity, leading to low-quality respiratory chain complexes that may degrade or yield less ATP and more ROS, increasing apoptosis risk. High mtEF4, however, boosts respiratory chain complexes production, raising ATP and ROS levels, vital for cellular energy and signaling	RNA extraction; qRT-PCR; western blot; TEM; OCR and ECAR, TCA metabolites assay; BNG and IGA; estimation of mitochondrial ROS production; detection of MMP; ATP assay; tumor growth assay; cell proliferation and apoptosis	NA	[10]
12	GBM	U251MG, U87MG, HaCaT cells (human keratinocyte cell line), GSCs, NSCs	Not given	Not given	NA	TUFM	Upregulated	Nanobody Nb206 binds TUFM interferes with GSCs and GBM cells’ proliferation and viability	Immunoaffinity enrichment (bio-panning); ELISA; mass spectrometry and antigen identification; qRT-PCR; western blotting; cytotoxicity measurements; apoptosis and necrosis, IHC	Nanobody-based targeting may bypass limitations of traditional antibodies, particularly in crossing the blood-brain barrier	[37]
13	Ovarian cancer	SW626, SK-OV-3 (ovarian cancer); HIOEC (normal ovarian epithelial); BJ-5ta (normal fibroblast)	NA	NA	SCID mice	Mitochondrial ribosomes	NA	Tigecycline specifically inhibits translation by mitochondrial ribosome but not nuclear or cytosolic ribosome, leading to mitochondrial dysfunction, oxidative stress and damage, AMPK activation and inhibition of mTOR signaling in ovarian cancer cells	Generation of mitochondrial DNA deficient r0 cell line; qRT-PCR, proliferation, cell cycle and apoptosis analysis, Mito stress test assay, measurement of oxidative stress and damage; xenograft ovarian cancer model	Tigecycline and cisplatin demonstrate synergistic effects in both in vitro and in vivo studies, suggesting potential for overcoming cisplatin resistance in ovarian cancer treatment	[58]
14	Osteosarcoma	MG63, U-2 OS, Saos-2, HOS	NA	NA	SCID mouse	TUFM	Upregulated	Knockdown of TUFM and tigecycline’s anti-cancer activities include inhibition of mitochondrial translation, suppression of Wnt/b-catenin, p21CIP1/WAF1 and miRNA-199b-5p-HES1 AKT pathway; Tigecycline selectively inhibits mitochondrial translation, impairs mitochondrial respiration, induces apoptosis in osteosarcoma cells	Drug and generation of mitochondrial DNA deficient r0 cell line; measurement of proliferation and apoptosis; siRNA knockdown and qRT-PCR; OCR; Measurement of mitochondrial biogenesis; osteosarcoma xenograft in SCID mouse	NA	[53]
15	AML	MOLM13-R1, MOLM13-R2, SU048-R	NA	Not given	NSG mice	MRPS29	NA	NA	Flow cytometric analysis; NSG xenotransplantation; drug treatment; leukemic burden analysis	Inhibition of mitochondrial translation is an effective approach to overcoming venetoclax resistance and provide a rationale for combining tedizolid, azacitidine, and venetoclax as a triple therapy for AML	[52]
16	BC	MCF7, ZR-75-1, BT-474, BT-549, MDA-MB-231, AU565, MDA-MB-361, control cell lines- MCF-10F	NA	NA	NA	NA	NA	GA-TPP+C10 causes: (1) Initial mitochondrial uptake and OXPHOS uncoupling; (2) Complex I inhibition; (3) αKGDHC inhibition; and (4) Induction of a glycolytic shift and AMPK-PGC1α mediated adaptive response. Doxycycline blocks: (1) Adaptive mitochondrial biogenesis by inhibiting mitochondrial translation; and (2) Leads to mitonuclear protein imbalance and synergistic cancer cell death when combined with GA-TPP+C10	MTT assay and crystal violet staining (cell viability); seahorse extracellular flux analysis (OCR and ECAR); qRT-PCR; western blot; flow cytometry (Annexin V/PI apoptosis assay, cell cycle analysis); αKGDHC activity assay; colony formation assay	Combination of a mitochondria-targeted metabolic inhibitor (GA-TPP+C10) and a mitochondrial translation inhibitor (doxycycline) demonstrates selective synergistic killing of breast cancer cells while sparing normal cells	[55]
17	GBM	NHA cells, HA cells, and U-87MG, U-138MG, U-251MG	n = 4	n = 61	Nude mice	MRPS16	Upregulated	MRPS16 over-expression remarkably promotes tumor cell growth, migration and invasion via the PI3K/AKT/Snail axis, which may be a promising prognostic marker for glioma	Western blotting; qRT-PCR; EdU; CCK-8; colony formation; transwell migration and invasion assays; coimmunoprecipitation	MRPS16 over-expression is a promising prognostic marker for glioma	[32]
18	GBM	U251MG, U87MG (mature GBM); NCH644, NCH421k (GSCs); HA cells	Not given	Not given	NA	TUFM	Upregulated	Nanobodies bind target proteins inhibit cell viability, induce apoptosis/necrosis, and reduce cell migration	qRT-PCR; ELISA; IHC; apoptosis/necrosis assays; cell migration assays	NA	[38]
19	GIST	GIST-T1 (KIT exon 11 mutation) and IM-resistant GIST-IR cells (induced via imatinib)	NA	NA	NA	TUFM	Upregulated	TUFM-knockdown decreased the proliferation and migration capacity of GIST-T1 and GIST-IR cells	TUFM silencing plasmids and electric transfection; qRT-PCR; western blotting; cell morphology and fluorescence assessment; cell proliferation and viability assays; wound healing and transwell assays; cell cycle determination	TUFM may serve as an effective target to inhibit early hematogenous metastasis, as well as postoperative recurrence and metastasis in patients with GIST, even in IM-resistant patients	[9]
20	HCC	Hepa 1-6, HepG2	Not given, GEO and TCGA dataset	Not given, GEO and TCGA dataset	C57 mice	MTIF2	Upregulated	MTIF2 suppression enhances apoptosis in HCC by modulating interactions with the apoptosis-inducing factor AIFM1, which can promote caspase3 expression. Also, down-regulation of MTIF2 impaired the proliferative and migratory abilities of HCC cells	Data acquisition and preprocessing; construction of co-expression network; establishment of module-trait relationship; pathway enrichment analysis; identification of hub genes, Cox risk regression and GSEA enrichment analysis; ATP assay; flow cytometry analysis; ELISA; cell viability assay; luciferase reporter assay; western blot analysis and IP	Overexpression MTIF2 impairs drug-induced immunogenic cell death in HCC, and a combination of treatment with MTIF2-knockdown may enhance the effect of chemotherapy	[42]
21	Cholangiocarcinoma	NA	NA	n = 36	NA	MRPL27	Upregulated	MRPL27 mainly involved in the processes of mitochondrial translation elongation, respiratory electron transport, ATP synthesis, and inner mitochondrial membrane organization	Survival analysis; PPI and enrichment, functional enrichment of interacted genes of MRPL27; identification of MRPL27 mutations	Upregulation of MRPL27 in tumor tissues predicted worse OS and DFS in cholangiocarcinoma patients	[15]
22	GBM	COMI, VIPI cells	NA	NA	NA	TUFM, MRPS18A	NA	Genetic inhibition of mitochondrial translation nearly completely abolished gliomasphere formation	Cas9 cell line generation; lentiviral vectors production; generation of knockout cell lines; viability assays; gliomasphere formation assay; cell cycle assay; apoptosis assay; autophagy assays; cryo-EM data and its processing; immunoblotting; immunofluorescence; RNA extraction; qRT-PCR; BNG and IGA assay, respiration assay; mitochondrial membrane potential assessment, lactate assay; competition assay	NA	[39]
23	BC	MCF-7, SKBR3, MDAMB231, MDAMB468, BU 25 TK, SiHa, HeLa, HTB34, SNU 638, AGS, NUGC, NCIH460, A549	NA	NA	NA	MRPS9, MRPS10, MRPS11, MRPS18B, MRPS31, MRPS33, MRPS38, MRPS39	MRPS10 and MRPS31- upregulated	MRPS proteins interact with non-mitoribosomal proteins (e.g., p53, ROS1, ACADSB). Involvement in cancer pathways: PIP3/AKT, MAPK, Wnt, Hedgehog, Estrogen signaling, G2/M transition, apoptosis, NF-κB, circadian rhythm	qRT-PCR, western blotting; MALDI; FPLC, GST pull-down assay; mass spectrometry; network and gene ontology analysis	MRPS10 and MRPS31 could serve as biomarkers or therapeutic targets in breast cancer	[44]
24	RCC	HK-2, 786-O, A498, Caki-2	NA	NA	Nude Mice	NA	NA	Doxycycline selectively inhibits mitochondrial protein translation in RCC cells, causing: (1) Disruption of ETC; (2) Decreased mitochondrial respiration (↓OCR); (3) Apoptosis and reduced proliferation; and (4) Synergistic effect with paclitaxel (a chemotherapy agent)	Cell proliferation and CI measurements; measurement of apoptosis; anchorage-independent colony formation; western blot analyses; qRT-PCR; mitochondrial complex activities; Mito stress assay	Doxycycline is a useful addition to the treatment strategy for RCC, mitochondrial translation inhibition in sensitizing RCC to chemotherapy	[56]
25	BC	NA	n = 291 (TCGA and GTEx databases)	n = 1085 (TCGA and GTEx databases)	NA	MRPL1, MRPL13, MRPS6, MRPS18C, MRPS35, MRPL16, MRPL40	MRPL1, MRPL13, MRPS6, MRPS18C, and MRPS35- upregulated; MRPL16, and MRPL40- downregulated	MRPL16 and MRPL40 were positively associated with survival outcomes, while MRPS18C and MRPS35 were inversely correlated with overall survival. MRPs are involved with cancer pathways like p21WAF1/CIP1, p27Kip1, and p53 for BC progression	Differential expression analysis; genomic alteration and methylation analysis; functional enrichment analysis and protein interaction visualization; survival analysis and prognostic model establishment	MRPs acted as biomarkers in individualized risk prediction and may serve as potential therapeutic targets in BC patients	[45]
26	BC	MCF10A (non-tumorigenic) MCF7 (ER/PR+), MDA-MB-231 (triple-negative)	NA	n = 26	NA	MRPs (MRPS29, MRPS18B, MRPS30, and MRPL11), TSFM, TUFM	Upregulated	Downregulation of MRPs and translation factors impaired mitochondrial translation reduced OXPHOS subunit expression (especially complex I and IV) → altered mitochondrial energy metabolism. Correlation with EMT markers (↑vimentin, ↓E-cadherin) indicates promotion of metastasis and invasiveness	Immunoblotting analyses; qRT-PCR; mitochondrial complex IV activity assays	NA	[11]
27	Liver cancer	Human PLC, HepG2, MDA-MB-468, A549, MCF7, HEK293T	NA	Not given	BALB/C nude mice	GFM2	NA	Translocated mitochondria PHGDH recruits the mitochondrial ribosome recycling factor mtEF4 via ANT2, facilitating subsequent cycles of mitochondrial translation and promoting liver cancer cell progression	RNA extraction; qRT-PCR; western blot; immunoprecipitation; mitochondria isolation, Mitochondrial translation assays; polysome profiling assay; in vitro GST pull-down assay; proliferation assay, immunofluorescence analysis; BNG; oxygen consumption measurements	NA	[41]
28	GBM	COMI and VIPI	NA	NA	NA	NA	NA	Inhibition of mitochondrial translation via binding to the peptidyl-transferase center of the mitoribosome. Impairment of OXPHOS complex assembly leading to GSC viability loss	Cryo-EM analysis of Q/D-mitoribosome interaction, Viability assays; mitochondrial and cytosolic protein synthesis assay, Immunoblotting; UHPLC-MS analysis	Q/D (Synercid®) is approved by the FDA for treating skin infections. The fluorine derivatives (16R)-1e, (16R)-2e, and flopristin are proposed for further in vivo testing against GBM	[40]
29	BC	MCF10A, MCF7, BT474, MDA-MB-361	Not given	n = 89 (METABRIC datasets, TCGA tumors)	MCF7 xenografts and PDX (HCI-017), NSG mice	TUFM	NA	CBFB (through hnRNPK) binds mt-mRNAs and promotes interaction with TUFM. CBFB deficiency impairs mitochondrial translation, ETC dysfunction, ↑glycolysis (Warburg effect), ↑autophagy/mitophagy. Cells become dependent on autophagy for survival, creating a therapeutic vulnerability	Bioinformatic analyses; RIP assay, immunofluorescence staining; confocal microscopy, and super-resolution microscopy; mitochondria fractionation; in situ mitochondrial translation assay; mitochondria stress test and glycolysis stress test; flow cytometry	Combination of PI3K inhibitor (BYL719) + autophagy inhibitor (HCQ) synergistically suppressed tumor growth	[30]
30	BC	MCF-7, MDA-MB-231, MDA-MB-436, SK-BR3	Not given (TCGA)	Not given (TCGA)	BALB/C nude mice	mtEF4	Upregulated	Upregulation of mtEF4 elevates the mitochondrial oxidative phosphorylation, which contributes to the migratory capacities of breast cancer cells. mtEF4 also increases the potential of glycolysis, probably via an AMPK-related mechanism	IHC; qRT-PCR; immunoblot; extracellular flux assay; ATP measurements, Isolation of mitochondria and IGA analysis; transwell assays; GEO and TCGA datasets analysis	The aberrantly upregulated mtEF4 contributes to the metastasis of breast cancer by coordinating metabolic pathways	[61]
31	B-cell lymphoma	Control-OCI-Ly7, OCI-Ly1;	NA	NA	WT mice, B-Tfam mice (Tfam deletion in B cells); Aicda-Tfam mice (Tfam deletion in germinal center B B cells); c-Myc lymphoma model	NA	NA	TFAM regulates mitochondrial transcription and translation in germinal center B cells. Deletion of TFAM: (1) Impairs mitochondrial remodeling; (2) Disrupts actin cytoskeleton; (3) Impairs motility and spatial organization of germinal center B cells; (4) Prevents proper germinal center formation and output; and (5) Inhibits lymphoma development (c-Myc model)	Flow cytometry; confocal and STED microscopy; 5-EU incorporation (RNA synthesis); OPP labeling (mitochondrial translation); spectral flow cytometry (ETC protein profiling); single-cell RNA-seq and V(D)J sequencing; IHC; OCR; adoptive transfer experiments; TFH-B cell co-culture; ELISA for affinity maturation; iGB (induced GC B cell) culture system	TFAM expression/activity as a biomarker for germinal center b cell activation and transformation	[33]
32	AML	NA	NA	n = 41	NA	MRPL10, MRPL22, MRPL11, MRPL54, MRPL12, MRPL16, MRPL20, MRPL24, MRPL28, MRPL38, MRPL57, MRPS18A, MRPS27	Upregulated	NA	Data analysis	Elevated expression of mitochondrial proteins may serve as a potential indicator of relapse risk in patients with AML who have the monocytic FAB subtypes M4 and M5	[51]
33	BC	MCF-10, MD A-MB-468, MD A-MB-453, MD A-MB-231, MCF-7	NA	NA	BALB/C nude mice	MRPS23	Upregulated	Promotes proliferation, migration, and EMT in breast cancer cells	Western blotting; cell migration and invasion assay; qRT-PCR; CCK-8; colony formation assay; transwell migration assays	MRPS23 can be a potential biomarker for aggressive breast cancer subtypes	[43]

HNSCC: Human head and neck squamous cell carcinoma; LC: Lung cancer; BC: Breast cancer; DLBCL: Diffuse large B-cell lymphomas; RCC: Renal cell carcinoma; HCC: Hepatocellular carcinoma; GBM: Glioblastoma multiforme; AML: Acute myeloid leukemia; GIST: Gastrointestinal stromal tumor; NA: Not available; GSC: Glioblastoma stem cell; NSC: Neural stem cell; NHA: Normal human astrocyte; HA: Human astrocyte; ER: Estrogen receptor; PR: Progesterone receptor; TCGA: The Cancer Genome Atlas; NSG: NOD-SCID-Il2rg(-/-); GEO: Gene Expression Omnibus; GTEx: Genotype-Tissue Expression; METABRIC: Molecular Taxonomy of Breast Cancer International Consortium; Tfam: Mitochondrial transcription factor A; MRPL: Mitochondrial ribosomal protein large subunit; TUFM: Mitochondrial elongation factor Tu; MRPS: Mitochondrial ribosomal protein small subunit; PTCD: Pentatricopeptide repeat domain; GFM1: Mitochondrial elongation factor G1; YARS2: Tyrosyl-transfer RNA synthetase 2; DARS2: Aspartyl-transfer RNA synthetase 2; PUS1: Pseudouridine synthase 1; mtEF4: Mitochondrial translation elongation factor 4; MTIF: Mitochondrial translation initiation factor; TSFM: Mitochondrial elongation factor Ts; GFM2: Mitochondrial translation elongation factor G2; COII: Cytochrome c oxidase subunit II; OXPHOS: Oxidative phosphorylation; EMT: Epithelial-mesenchymal transition; AMPK: Adenosine monophosphate-activated protein kinase; GSK3β: Glycogen synthase kinase 3β; NLRX1: NOD-like receptor X1; eIF2α: Eukaryotic initiation factor 2α; EGFR: Eukaryotic initiation factor 2α; UPR: Unfolded protein response PI3K: Phosphoinositide 3-kinase; AKT: Protein kinase B; TNM: Tumor-node-metastasis; DDX3: DEAD box RNA helicase; ATP: Adenosine triphosphate; ROS: Reactive oxygen species; p21CIP1: Cyclin-dependent kinase interacting protein 1; WAF1: MiRNA-199b-5p-HES1; αKGDHC: Α-ketoglutarate dehydrogenase complex; PGC1α: Peroxisome proliferator-activated receptor gamma coactivator 1α; ACADSB: Acyl-CoA dehydrogenase, short/branched chain B; NF-κB: Nuclear factor kappa-light-chain-enhancer of activated B cells; ETC: Electron transport chain; OCR: Oxygen consumption rate; MRP: Mitochondrial ribosomal protein; p21WAF1: P21 wild-type p53-activated fragment 1; CIP1: CDK-interacting protein 1; p27Kip1: P27 kinase inhibitory protein 1; PHGDH: Phosphoglycerate dehydrogenase; ANT2: Adenine nucleotide translocase 2; CBFB: Core binding factor beta; hnRNPK: Heterogeneous nuclear ribonucleoprotein K; mt-mRNA: Mitochondrial messenger RNA; ETC: Electron transport chain; qRT-PCR: Quantitative reverse transcriptase polymerase chain reaction; NAD1: Nicotinamide adenine dinucleotide; NADH: Nicotinamide adenine dinucleotide hydride; IHC: Immunohistochemistry; RNAi: RNA interference; TMA: Tissue microarray; shRNA: Short hairpin RNA; OCR: Oxygen consumption rate; iTRAQ: Isobaric tags for relative and absolute quantitation; SRC: Spare respiratory capacity; DLBCL: Diffuse large B-cell lymphomas; EF-Tu: Elongation factor Tu; RNA-seq: RNA sequencing; TEM: Transmission electron microscopy; ECAR: Extracellular acidification rate; TCA: Tricarboxylic acid cycle; BNG: Blue native polyacrylamide gel electrophoresis; IGA: In-gel activity; MMP: Mitochondrial membrane potential; ELISA: Enzyme-linked immunosorbent assay; siRNA: Small interfering RNA; MTT: 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide; EdU: 5-ethynyl-2’-deoxyuridine; Co-IP: Coimmunoprecipitation; IP: Immunoprecipitation; PPI: Protein-protein interaction; cryo-EM: Cryogenic electron microscopy; MALDI: Matrix-assisted laser desorption/ionisation; FPLC: Fast protein liquid chromatography; GST: Glutathione S-transferase; CI: Combination index; UHPLC-MS: Ultra-high performance liquid chromatography-mass spectrometry; RIP: RNA immunoprecipitation; PLA: Proximity ligation assay; 5-EU: 5-Ethynyluridine; OPP: O-propargyl-puromycin; iGB: Induced germinal center B cell; mtDNA: Mitochondrial DNA; IM: Imatinib mesylate; OS: Overall survival; DFS: Disease-free survival; FDA: Food And Drug Administration; HCQ: Hydroxychloroquine; FAB: French-American-British classification.

While cytosolic translation has been extensively studied, mitochondrial translation remains underexplored, especially its role in key cancer hallmarks such as sustained proliferative signaling, resistance to cell death, invasion, and metastasis. This review aims to establish a foundation for understanding mitochondrial translation in cancer and explore its potential as a therapeutic target, leveraging its unique role in tumor biology for more effective treatments.

LITERATURE REVIEW

Search strategy

We followed the Preferred Reporting Items for Systematic reviews and Meta-Analyses criteria ensured a thorough and organized synthesis of pertinent material. The literature search was conducted by the primary author (Agarwal N) under the regular supervision and direction of a senior researcher (Sharma U). A comprehensive electronic search strategy was implemented utilizing the following Boolean search string across multiple databases: [(“Cancer”) OR (“Tumor”) OR (“Carcinoma”) OR (“Malignancy”) OR (“Neoplasm”) OR (“Sarcoma”) OR (“Lymphoma”) OR (“leukemia”)] AND (“Mitochondrial translation”). The search was limited to publications indexed between March 2014 and February 2025. In the primary literature search, detailed information was retrieved from Web of Science, Scopus, PubMed, and EMBASE, accessed on April 7, 2025. Initial screening of retrieved records was based on title and abstract evaluation. Following a rigorous selection process, 1225 articles met the inclusion criteria, as depicted in Figure 1.

Figure 1 Preferred Reporting Items for Systematic reviews and Meta-Analyses flow chart outlining the literature search and study selection process. All cartoons in this figure were prepared using BioRender (Supplementary material).

Inclusion and exclusion criteria

Only original research articles that addressed mitochondrial translation in various malignancies were taken into consideration due to our strict inclusion criteria. Several studies were found by an initial thorough web search; duplicate entries were removed from these studies (n = 755) to get rid of redundant information. Furthermore, during the database search, non-primary research sources were eliminated. Among these removed materials were review articles, abstracts from conferences, book chapters, encyclopedias, meta-analyses, patents, and grey literature. Articles that discussed other translational mechanisms or disorders or that just had a passing connection to mitochondrial translation were also disqualified from this review (n = 1192). Lastly, the review included (n = 33) peer-reviewed original research articles that satisfied the inclusion requirements. These selected studies provide critical insights into the role of mitochondrial translation in cancer, reveal potential therapeutic targets across diverse tumor types, and propose innovative strategies to overcome treatment resistance.

MITOCHONDRIAL TRANSLATION: MECHANISM AND MACHINERY

Mitochondrial translation is the process by which mitochondria synthesize proteins encoded by its own mtDNA. This process is essential for the proper functioning of the OXPHOS system, which is responsible for ATP production in eukaryotic cells[16]. Human mtDNA encodes for 13 essential polypeptides, all of which are integral components of the OXPHOS complexes. Additionally, mtDNA encodes 22 tRNAs and 2 rRNAs necessary for mitochondrial protein synthesis, as shown in Figure 2[4,16]. The mitochondrial translation takes place in the matrix of the mitochondrion and is performed by dedicated machineries, such as the mitochondrial ribosome (mitoribosome), tRNAs, and translation factors[4]. The proteins required for assembly of mitoribosomes and the translation factors are encoded by nuclear DNA and are imported into mitochondria, whereas the rRNAs and tRNAs are encoded by mtDNA. These mitoribosomes differ structurally from cytoplasmic ribosomes, as mitoribosomes are composed of a small 28S subunit and a large 39S subunit, forming a 55S ribosome, whereas cytoplasmic ribosomes are composed of smaller 40S subunits and larger 60S subunits, forming an 80S ribosome. Also, mitoribosomes have 2 rRNAs (16S and 12S) compared to cytoplasmic ribosomes which have 4 rRNAs (28S, 5.8S, 5S and 18S; Figure 3). The mitoribosomes are made up of unique proteins known as MRPs which are absent in cytoplasmic ribosomes. These MRPs are nuclear-encoded and form the protein scaffold of mitochondrial ribosomes and also play roles in ribosome assembly and rRNA stabilization[17]. The MRPs of larger subunit are denoted as MRPL (approximately 50 proteins) and of smaller subunit are denoted by MRPS (approximately 30 proteins). Unlike cytoplasmic translation, which involves complex regulatory mechanisms, mitochondrial translation relies on fewer initiation factors and simpler messenger RNA (mRNA) structures[4,18].

Figure 2 Structure of mitochondrial DNA. tRNA: Transfer RNA; rRNA: Ribosomal RNA; mRNA: Messenger RNA. All cartoons in this figure were prepared using BioRender (Supplementary material).

Figure 3 Schematic representation of mitochondrial translation. A-C: Initiation: The small mitochondrial ribosomal subunit (28S) associates with messenger RNA (mRNA) and initiator formylmethionyl-transfer RNA, facilitated by initiation factors mitochondrial initiation factor 2 and mitochondrial initiation factor 3 The large subunit (39S) then joins to form the complete 55S mitoribosome; D and E: Elongation: Aminoacyl-transfer RNAs are delivered to the ribosome by the elongation factor mitochondrial elongation factor Tu, and peptide bond formation occurs. Mitochondrial elongation factor Ts helps in the exchange of guanosine triphosphate with guanosine triphosphate for mitochondrial elongation factor Tu, and mitochondrial elongation factor G1 assists in the translocation step; F and G: Termination: Release factors (Mitochondrial release factor 1A) promote polypeptide chain release upon reaching a stop codon; H and I: Ribosome recycling: Ribosome recycling factors (mitochondrial ribosome recycling factor, mitochondrial elongation factor G2) facilitate dissociation of the ribosomal subunits and release of mRNA. Inset (left): The ribosome’s E, P, and A sites and the entry/exit channels for mRNA. Inset (bottom left): Legend of translation factors and cofactors involved in each step. fMET: Formylmethionyl; tRNA: Transfer RNA; mRNA: Messenger RNA; MTIF: Mitochondrial initiation factor; TUFM: Mitochondrial elongation factor Tu; TSFM: Mitochondrial elongation factor Ts; GFM1: Mitochondrial elongation factor G1; MTRF1 L: Mitochondrial release factor 1A; GFM2: Mitochondrial elongation factor G2; MRRF: Mitochondrial ribosome recycling factor; GTP: Guanosine triphosphate; GDP: Guanosine diphosphate. All cartoons in this figure were prepared using BioRender (Supplementary material).

Mitochondrial translation occurs in four main stages: Initiation, elongation, termination, and ribosome recycling. The initiation phase involves assembling the 28S small subunit with formylmethionyl-tRNA for methionine, mRNA, and two initiation factors, MTIF2 and MTIF3, as illustrated in Figure 3[4,18]. Unlike bacterial or cytoplasmic systems, mitochondrial initiation does not require a third factor [e.g., initiation factor 1 in bacteria or eukaryotic initiation factor 1 in cytoplasmic translation]. The formylation of the methionine residue plays a crucial role in mitochondrial translation, as it is necessary for MTIF2 to increase its affinity for tRNA as MTIF2 binds directly to the formylmethionyl-tRNA for methionine, stabilizing its interaction with the small subunit, as illustrated in Figure 3. This feature is not present in cytoplasmic translation as it is not required[4,18]. Notably, MTIF2 possesses a unique 37-amino acid insertion domain that mimics the bacterial initiation factor 1, blocking the aminoacyl (A) site of the ribosome during initiation, as shown in Figure 3[18]. This insertion domain ensures proper positioning of formylmethionyl-tRNA for methionine and prevents premature elongation[18]. MTIF3 facilitates the correct positioning of the AUG initiation codon within the peptide (P) site of the small subunit. It stabilizes the mRNA-small subunit interaction and prevents premature binding of elongation factors[16]. Cryogenic electron microscopy studies reveal that MTIF3 interacts with the mitoribosomal protein mitochondrial small subunit ribosomal protein 37, keeping the small subunit in a conformation suitable for initiation[4]. Mitochondrial mRNAs lack a 5’ untranslated region and are leaderless, differing from cytoplasmic mRNAs, which require a 5’ cap and scanning mechanism for initiation. This structural simplicity allows direct binding of the mRNA to the small subunit, eliminating the need for helicase activity, such as that performed by eukaryotic initiation factor 4A in cytoplasmic translation (Figure 3)[4,19].

Next is elongation, which involves tRNA binding, peptide bond formation, and ribosomal translocation. Mitochondrial elongation factors include TUFM, mitochondrial elongation factor Ts (TSFM), and GFM1[4,20]. TUFM delivers aminoacyl-tRNA (aminoacyl-tRNA) to the A site of the ribosome, ensuring codon-anticodon pairing whereas TSFM regenerates TUFM-guanosine triphosphate by displacing guanosine diphosphate, enabling repeated rounds of tRNA delivery, as illustrated in Figure 3[4], and GFM1 facilitates translocation of the ribosome along the mRNA, moving the tRNA from the A site to the P site and the E site to the exit, as depicted in Figure 3. Cryogenic electron microscopy structures reveal that GFM1 induces large-scale conformational changes in the small subunit head, enabling mRNA-tRNA movement[20]. mtEF4 plays a role in the reverse movement of post-translational ribosomes[21]. It is capable of identifying faulty ribosomes during the translocation process and triggers their backward movement toward the 5’ end of the mRNA, a process known as backward translocation. By doing so, mtEF4 offers a second chance for accurate tRNA translocation to occur[22,23].

Translation termination in mitochondria is mediated by mitochondrial release factor. Human mitochondria contain four members of the class 1 release factor family: Mitochondrial release factor (MTRF) 1A (MTRF1 L), MTRF1, MTRF in rescue (previously known as C12orf65), and MRPL58 (previously known as immature colon carcinoma transcript 1)[24]. MTRF1 and MTRF1 L recognize stop codons and trigger peptide release from the P site tRNA, as shown in Figure 3[25]. There are two types of stop codons in mitochondria, canonical (UAA, UAG) and non-canonical (AGA, AGG), whereas the cytoplasm has canonical stop codons (UAG, UGA and UAA). These non-canonical codons are unique to mitochondria because they lack cognate tRNAs in the mitochondrial translation system, having been reassigned from their usual arginine-coding function. The AGA codon is located at the end of cytochrome c oxidase subunit 1 gene whereas AGG is located at the end of nicotinamide adenine dinucleotide hydrogen dehydrogenase subunit 6 gene[26]. MTRF1 L recognizes canonical stop codons UAA and UAG and is responsible for terminating translation of 11 out of 13 mitochondrial proteins[27,28]. It contains a conserved codon recognition domain similar to bacterial release factor 1 and utilizes direct base-specific interactions with mRNA stop codons[26,27]. On the other hand, MTRF1 specifically recognizes and terminates translation at non-canonical stop codons AGA and AGG. It contains specific insertions in the codon recognition domain not found in MTRF1 L[26,27]. This extended codon recognition loop pushes the first two bases (AG) of the stop codon toward the head region of the small ribosomal subunit and creates a unique binding mode where the stop codon is repositioned rather than directly contacted[26,27].

Finally, ribosome recycling separates the mitoribosomal subunits (28S and 39S) and releases mRNA/tRNA, enabling reinitiation. This process is facilitated by mitochondrial elongation factor G2 (GFM2) and MRRF, as depicted in Figure 3[29]. GFM2 promotes the dissociation of the subunits through guanosine triphosphate hydrolysis, in contrast to the ATP hydrolysis seen in cytoplasmic ribosome recycling. GFM1 interacts with MRRF, which binds to the A site, enabling the release of mRNA/tRNA, as illustrated in Figure 3. Unlike GFM1, GFM2 does not possess the structural motifs necessary for translocation and instead specializes in the recycling process[29].

Mitochondrial translation is optimized for synthesizing OXPHOS components. Its structural simplicity (leaderless mRNAs, fewer initiation factors) contrasts with the complexity of cytoplasmic translation, which requires scanning, capping, and extensive regulatory machinery[5,16]. Understanding these distinctions provides critical insights into mitochondrial biology, disease mechanisms, and evolutionary adaptation[4].

IMPLICATIONS OF MITOCHONDRIAL TRANSLATION IN HALLMARKS OF CANCER

Mitochondrial translation and its regulatory parameters play a vital role in numerous fundamental features of cancer, such as persistent proliferation, resistance to apoptosis, and the ability to invade and metastasise[10,30]. Cancer cells demand enhanced generation of ATP and anabolic support, which are both strongly linked to the activity of mitochondria[31]. Modifications in mitochondrial translation stimulate metabolic reprogramming, leading to uncontrolled proliferation. Similarly, mitochondrial dysregulation inhibits apoptosis by compromising ATP/reactive oxygen species (ROS) balance and apoptotic signaling pathways, enhancing cell survival and decreasing drug resistance[9]. Additionally, mitochondrial translation impacts cytoskeletal dynamics, epithelial-mesenchymal transition (EMT), and availability of energy, which promotes tumor cell motility, invasion, and potential for metastatic spread[11]. Mitochondrial translation regulators, including mtEF4 and MRPS16, have been linked to cytoskeletal reorganization, cell motility, and signaling pathways that promote metastatic dissemination[10,32,33]. Consequently, this section provides a comprehensive investigation of how dysregulation of mitochondrial translation contributes to these essential characteristics of cancer progression.

Sustained proliferative signaling

Sustained proliferative signaling refers to the ability of cancer cells to continuously receive and transmit growth signals, which enables them to divide uncontrollably. These proliferating cells depend on large amounts of ATP and biosynthetic precursors, both of which are produced by functional mitochondria[10]. Efficient mitochondrial translation is crucial as it supplies ATP through OXPHOS and provides the necessary building blocks for cellular anabolism[31]. The dysregulated mitochondrial translation factors play a significant role in supporting cancer cell proliferation across various tumor types by driving metabolic reprogramming and bypassing cellular checkpoints[30]. For example, TUFM is highly expressed in PCI-13 and UDSCC2 (HNSCC cell lines), and it forms a mitochondrial complex along with nod-like receptor X1 that triggers autophagy and counters anti-proliferative effects in HNSCC cells[34]. Also, the upregulation of TUFM protein is associated with the progression of colorectal cancer through colorectal adenoma-to-carcinoma transformation and correlates with poor clinical outcomes, suggesting that TUFM could serve as an important prognostic factor for cancer patients[35]. The knockdown of TUFM along with tigecycline treatment in renal cell carcinoma cells leads to reduced cell growth and survival as a consequence of the suppression of essential growth/ survival signaling pathway phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT)/mTOR, as illustrated in Figure 4 and Table 1[36].

Figure 4 Mechanism of mitochondrial translation factors. The inner blue circle contains all the translation factors. The outer orange circle represents the downstream mechanism of the translation factors. All cartoons in this figure were prepared using BioRender (Supplementary material).

Emerging studies have used anti-TUFM nanobodies (Nb206) to target TUFM in glioblastoma multiforme, as TUFM is highly expressed in glioblastoma multiforme cell lines [U87MG, U251MG and glioblastoma stem cells (GSCs)] compared to neural stem cells[37]. Nb206 significantly inhibited the proliferation of U87MG and GSCs in a dose-dependent manner[37]. Similar results were found with Nb225 anti-TUFM nanobody in glioblastoma[38]. In GISTs, it was found with the help of the Cell Counting Kit-8 (CCK-8) assay that the knockdown of TUFM inhibited the proliferation rate of GIST cells[9]. In breast cancer, with the help of the Ki67 assay, it was observed that impairing mitochondrial translation by knocking down core binding factor beta led to reduced proliferation of MCF10A cells[30]. Furthermore, the researchers evaluated the effect of knocking out the TUFM and MRPS18A genes on GSCs that were grown as glioma spheres. The size of glioma spheres was measured over 15 days, and the results showed a significant reduction in the size of the glioma spheres in the TUFM and MRPS18A knockout cells compared to the normal cells[39,40]. In another study, with the help of tumor formation assay it was found that elevated expression of mtEF4 increases the production of respiratory chain complexes and levels of both ATP and ROS in cells, which leads to increased cellular proliferation in lung, cervical, esophageal, and bladder cancers[10]. In liver cancer, depletion of GFM2 expression reduces phosphoglycerate dehydrogenase (PHGDH) mediated tumor growth[41]. Mechanistically, PHGDH forms a complex with adenine nucleotide translocase 2 to recruit GFM2. This recruitment promotes the efficiency of mitochondrial ribosome recycling, mitochondrial translation and respiration, leading to increased tumor growth[41]. Also, with the help of 5-ethynyl-2’-deoxyuridine (EdU) incorporation assay it was found that downregulation of MTIF2 impaired the proliferation of HCC cells[42]. Similarly, high levels of MRPS23 can predict poor clinical outcomes in HCC, and it plays an important role in tumor proliferation, as the downregulation of MRPS23 in HCC cells leads to reduced colony formation and tumor growth in vitro and in vivo conditions (Table 1)[14]. As assessed by CCK-8 and EdU assays, the knockdown of MRPS23 in breast cancer cells led to reduced proliferation compared to control cells[43]. One of the studies, with the help of molecular pathway enrichment analysis and co-expression modules identification tool, showed that MRPS10 and MRPS31 in breast cancer interact with short/branched-chain acyl-CoA dehydrogenase, an enzyme critical for fatty acid oxidation (FAO) linked to the brain-derived neurotrophic factor (BDNF) pathway[44]. Short/branched-chain acyl-CoA dehydrogenase is imported into mitochondria as a precursor and processed to its mature form within the mitochondrial matrix, where it participates in β-oxidation. It is a transcriptional target of BDNF and is associated with increased FAO and may interact with mitoribosomes. Abnormal FAO activity has been implicated in various cancer aspects, including proliferation, survival, stemness, drug resistance, and metastasis[44]. Also, another study showed that low levels of MRPL16 and MRPL40, along with high expression of MRPL1, MRPL13, MRPS6, MRPS18C, and MRPS35, significantly indicated poor prognosis in BC patients, as shown in Figure 4 and Table 1[45].

In colorectal cancer, MRPL33-L can promote cancer cell growth, as its knockdown in SW620 and HT29 colon cancer cells showed growth repression, observed by colony forming assay[46]. Furthermore, the expression of MRPL11 was found to be 2-fold decreased in HN8 cells (HNSCC cell line) compared to HaCat cells (normal cell line) and a reduced expression of MRPL11 was observed in some patients of HNSCC[13]. This impairment in mitochondrial translation due to reduced expression of MRPL11 Leads to defective synthesis of mitochondrial-encoded proteins (e.g., subunit of complex IV), which in turn impairs OXPHOS[13]. This defect potentially forces a metabolic shift to aerobic glycolysis (Warburg effect), aiding tumor survival and progression, particularly in metastatic sites[13]. MRPS16 is highly expressed in glioblastoma, and its over-expression in U-138MG cells using lentiviruses leads to enhanced tumor cell growth measured by CCK-8, EdU, colony formation, and transwell and vice versa in MRPS16 knockdown cells[32]. Notably, with the help of dual luciferase reporter assays, it was confirmed that knockdown of MRPS16 inhibits PI3K/AKT signaling (Table 1)[32]. Additionally, Snail, phosphorylated-AKT and phosphorylated-PI3K protein levels were found to be significantly decreased in MRPS16 knockdown cells, as shown by western blot. These findings demonstrated that MRPS16 facilitates tumor development through the PI3K/AKT/Snail pathway[32]. A recent study showed that mitochondrial translation plays a vital role in maintaining respiratory activity, as well as supporting the growth and survival of Eμ-Myc lymphoma cells[8]. When the researchers knocked down MRPS39, MRPS5 or MRPS27, they observed a reduction in the expression of mitochondrial-encoded proteins and a decline in respiration rates, both of which proved harmful for the growth of the lymphomas[8]. The elevated levels of mitochondrial translation, which are facilitated by the expression of mitochondrial transcription factor A (TFAM), are crucial for the progression and development of B-cell lymphoma[33]. This indicates that TFAM plays a significant role in maintaining mitochondrial function and energy production[47,48], which are necessary for the survival and proliferation of malignant B-cells. Therefore, by depleting TFAM expression, mitochondrial translation was affected, and ultimately, the proliferation of B-cell lymphoma cells was compromised, as illustrated in Figure 4 and Table 1[33].

These observations highlight the mitochondrial translation machinery as a vital player in cancer metabolism, presenting new avenues for targeted therapies aimed at inhibiting factors such as MTIF2, TUFM, mtEF4, GFM2, MRPS16, or MRPS23 to disrupt cancer cell proliferation. These factors enable metabolic reprogramming that bypasses cellular checkpoints, with TUFM overexpression correlating with poor clinical outcomes in colorectal cancer progression and reduced cell survival when inhibited across multiple cancer types including glioblastoma, breast, and liver cancers. The dysregulation of MRPs like MRPS23, MRPL33, and others demonstrates their dual role in promoting tumor growth while offering potential therapeutic targets, as their knockdown consistently reduces proliferation rates and tumor formation across various cancer models. Collectively, these mitochondrial translation components represent both prognostic biomarkers and promising therapeutic vulnerabilities in cancer treatment strategies.

Resistance to cell death

Resistance to apoptosis, a form of programmed cell death, is a hallmark characteristic of cancer cells and significantly contributes to the progression and survival of tumors[46]. This resistance allows cancerous cells to evade the normal regulatory processes that trigger cell death in response to various stressors, including DNA damage and oxidative stress. Recent research has highlighted the potential of targeting mitochondrial translation as a therapeutic strategy to induce apoptosis in these resistant cancer cells. Like, in glioblastoma multiforme, researchers have used NB206 nanobody to target TUFM, and they found that there was a significant reduction in the cell viability at 100 μg/mL Nb206 after 48 hours of incubation in GSCs, U87MG and U251MG (Table 1)[37]. Similarly, Nb225 nanobody also showed a significant increase in apoptosis, as illustrated in Figure 4 and Table 1[38]. In another study, it was found that low mtEF4 levels increase mitochondrial translation but decrease translational fidelity[10]. As a result, the respiratory chain complexes produced are of low quality, which may lead to less ATP and more ROS. All these changes increase the risk of apoptosis in lung, cervical, esophageal, and bladder cancers as observed by the increased levels of cleaved caspase-3 in the cells, which were knocked down for mtEF4, as shown in Figure 4 and Table 1[10]. Also, MTIF2 suppression enhances apoptosis in HCC by modulating interactions with the apoptosis-inducing factor apoptosis-inducing factor mitochondria-associated (AIFM) 1, as MTIF2 normally binds directly to AIFM1 in the mitochondrial intermembrane space, blocking AIFM1’s pro-apoptotic functions. The knockdown of MTIF2 frees AIFM1 allowing it to undergo calpain-mediated cleavage and translocate to the nucleus where it facilitates large-scale DNA fragmentation and acts as a transcriptional co-activator for the caspase 3 gene promoter, increasing caspase 3 mRNA and protein levels, as shown in Figure 4 and Table 1[42,49]. And in diffuse large B-cell lymphomas (DLBCL), GFM1, TUFM, and MRPS7 were depleted using short hairpin RNAs in oxidative phosphorylation- and non-oxidative phosphorylation/B-cell receptor-DLBCL cell lines, and found a significant cell death in OXPHO-DLBCL cells compared to non-OxPhos/B-cell receptor-DLBCL (Table 1)[50].

Studies reveal widespread dysregulation of MRPs, including smaller (MRPS) and larger (MRPL) subunit genes, across diverse malignancies such as renal cell carcinoma, ovarian cancer, osteosarcoma, glioblastoma, breast cancer, and acute myeloid leukemia[36,46,39,51-54]. In acute myeloid leukemia, knockdown of DAP3 (MRPS29) along with venetoclax leads to apoptosis induction. This happens because it activates a response called the integrated stress response. This response can lead to an increase in the production of proteins that cause cell death, such as B-cell lymphoma 2 interacting mediator of cell death, while lowering levels of proteins that protect against cell death, like myeloid cell leukemia 1. This process makes the cells more likely to undergo apoptosis 52]. Also, the knockdown of MRPL33-L in SW620 and HT29 colon cancer cells significantly activates apoptosis, as indicated by the presence of cleaved poly(ADP-ribose) polymerase-1, a known apoptosis marker[46]. In breast cancer cells and renal cell carcinoma cells, by using doxycycline mitochondrial translation was inhibited, leading to cancer cell death as doxycycline blocks the A-site of tRNA on 28S small subunit of mitoribosome[55,56]. Furthermore, in breast cancer cells, DEAD box RNA helicase (DDX3) is inhibited by RK-33. DDX3 plays a role in mitochondrial homeostasis by translocating to mitochondria where in response to mitochondrial stress, it facilitates the translation of phosphatase and tensin homology-induced kinase 1[57]. Inhibition of DDX3 suppresses mitochondrial biogenesis and mitophagy, which leads to increased ROS and apoptosis due to a reduction in Mitochondrial-encoded proteins expression, OXPHOS capacity and ATP production, as illustrated in Figure 4 and Table 1[54].

Tigecycline also acts on mitochondrial ribosomes by blocking the A-site of tRNA on 28S small subunit, leading to the inhibition of mitochondrial translation[58,59]. In ovarian cancer cells treated with tigecycline, researchers observed a notable reduction in both basal and maximal mitochondrial respiration, along with an increase in cellular levels of ROS and the oxidative DNA damage marker 8-hydroxy-2’-deoxyguanosine[58]. Additionally, there was an elevation in phosphorylated adenosine monophosphate-activated protein kinase (AMPK) and a decrease in phosphorylated mTOR in the tigecycline-treated cells as inhibition of mitochondrial translation by tigecycline impairs electron transport chain function, leading to an increased adenosine monophosphate/ATP ratio that allosterically activates AMPK. Furthermore, activated AMPK phosphorylates key components of the mechanistic target of rapamycin complex 1 pathway, leading to the inhibition of mTOR signaling pathway[60]. This suggests that tigecycline activates AMPK and suppresses mTOR signaling as a result of mitochondrial dysfunction leading to increased apoptosis[58]. Similarly, in osteosarcoma, tigecycline and knockdown of TUFM selectively inhibit mitochondrial translation, impair mitochondrial respiration and induce apoptosis in osteosarcoma cells, as shown in Figure 4 and Table 1[53]. Collectively, aberrant expression of mitochondrial translation factors and MRPs fosters resistance to cell death, enabling tumor persistence. Targeting these components could disrupt mitochondrial function, amplify oxidative stress, impair energy production, activate integrated stress response, and reduce pro-survival signaling, ultimately tipping the balance toward cancer cell death.

Invasion and metastasis

Invasion and metastasis remain key hallmarks of cancer progression, often determining patient prognosis and therapeutic outcomes. Recent evidence suggests that mitochondrial function, particularly mitochondrial translation, plays a critical role in driving these aggressive phenotypes. In lung cancer and breast cancer, it was observed that knockdown of TUFM triggered EMT, decreased the activity of the mitochondrial respiratory chain, and enhanced glycolytic activity along with the generation of ROS[31]. From a mechanistic perspective, TUFM knockdown activated AMPK, leading to the phosphorylation of glycogen synthase kinase-3β and increased the nuclear presence of β-catenin, which resulted in the promotion of EMT and increase in migration and metastasis of A549 Lung cancer cells and MCF7 breast cancer cells, as evaluated by the increased levels of E-cadherin, and decreased levels of N-cadherin, and fibronectin[31]. Also, in GISTs, the expression of TUFM is positively correlated with the risk of tumor metastasis[9]. The wound healing assays showed that silencing TUFM significantly reduced the migratory rate of GIST-T1 and GIST-IR cells compared to the control groups after 48 hours of transfection, as illustrated in Figure 4 and Table 1[9].

In breast cancer, the downregulation of translation factors (TUFM and TSFM) and MRPs (DAP3, MRPS18B, MRPS30, and MRPL11) impairs mitochondrial translation, which leads to reduced OXPHOS subunit expression (especially Complex I and IV) and altered mitochondrial energy metabolism[11]. These changes correlate with EMT markers (↑Vimentin, ↓E-cadherin), indicating promotion of metastasis and invasiveness, as shown in Figure 4 and Table 1[11]. Furthermore, functionally, mtEF4 promotes the assembly of mitochondrial respiratory complexes, enhancing OXPHOS and ATP production (Table 1)[61]. This increase in cellular energy supports the formation of lamellipodia and actin cytoskeleton remodeling, structures essential for cell motility and invasion[61]. It is observed that when mitochondrial translation becomes dysregulated, cells respond with dramatic cytoskeletal reorganization[62]. Mitochondrial dysfunction triggers rapid actin polymerization around damaged organelles, mediated by the actin-related protein 2/3 complex and occurs within minutes of mitochondrial damage and promoting glycolytic activation. This rapid response helps cells compensate for impaired OXPHOS by enhancing cytoplasmic glucose metabolism[62]. In breast cancer, knockdown of mtEF4 not only disrupts these cytoskeletal changes (checked by expression of cortactin) but also impairs migration and invasion in vitro and significantly reduces metastatic burden in MDA-MB-231 cells (assessed by transwell membrane assay)[61]. Also, overexpression of MRPS23 leads to increased migration and invasion of breast cancer cells (MDA-MB-231) after 48 hours of incubation compared to the control group, assessed by scratch and wound healing assay[43]. And, the knockdown of MRPS23 leads to the reduced expression of E-cadherin, N-cadherin, Snail1 and TWIST1, which indicates silencing of MRPS23 attenuates the EMT process[43]. In gliomas, overexpression of MRPS16, an MRP, activates the PI3K/AKT/Snail axis, a well-established pathway driving EMT and metastasis. Silencing MRPS16 reduces cell migration and invasion, further supporting the role of mitochondrial translation machinery in promoting tumor aggressiveness[32]. And finally, as mentioned earlier in sections 4.1 and 4.2, since MTIF2 is significantly expressed in HCC, the impact of downregulating MTIF2 levels on the migration of HCC cells was checked through a wound healing assay and a transwell assay. The findings revealed that downregulation of MTIF2 also impaired the migratory ability of HCC cells, as illustrated in Figure 4 and Table 1[42]. In summary, the accumulating evidence underscores a critical link between mitochondrial translation and cancer metastasis across multiple tumor types. Disruption of mitochondrial translation factors such as TUFM, TSFM, mtEF4, and various MRPs alters mitochondrial respiration. This impairment may then facilitate EMT via the AMPK/glycogen synthase kinase-3β signaling pathway. Additionally, these disruptions lead to cytoskeletal remodeling through the actin-related protein 2/3 complex, which is responsible for actin polymerization. As a result, cancer cells may exhibit enhanced migratory and invasive capabilities through the activation of pathways such as PI3K/AKT/Snail.

All these findings suggest that mitochondrial translation is not merely a metabolic process but a central regulator of the cancer hallmarks (sustained proliferative signaling, resistance to apoptosis and invasion and metastasis), likely through interconnected pathways involving energy metabolism, ROS signaling, cytoskeletal remodeling, and EMT transcriptional programs. Firstly, sustained proliferation is driven by overexpression of factors such as TUFM, mtEF4 and MRPS23, which enhance OXPHOS-derived ATP and biosynthetic precursors to fuel cell division, with inhibition via tigecycline, nanobodies or genetic knockdown consistently reducing tumor growth. Secondly, resistance to apoptosis arises when impaired translation factors (e.g., MTIF2, GFM1, MRPS16) disrupt mitochondrial membrane potential and ROS/AMPK signaling, thereby blocking intrinsic death pathways, while restoring their function or targeting them reactivates caspase-dependent cell death. Finally, invasion and metastasis are promoted by translational defects that alter cytoskeletal dynamics and EMT programs, driven by mtEF4, MRPS16 and MRPL11, enabling motility and colonization, whereas correcting translational imbalance impairs migratory and invasive behavior. Thus, targeting components of the mitochondrial translation machinery may represent a promising therapeutic strategy to curb tumor progression and metastasis.

CONCLUSION

The intricate regulation of mitochondrial translation plays a pivotal role in orchestrating core hallmarks of cancer, including sustained proliferation, resistance to cell death, and enhanced metastatic potential. Although mitochondrial metabolism has long been recognized as a key player in oncology, the specific contributions of translational regulation have remained underexplored. This review has systematically delineated how dysregulation of mitochondrial translation factors and mitoribosomal proteins drives metabolic reprogramming, compromises apoptotic checkpoints via ROS/AMPK and PI3K/AKT pathways, and facilitates cytoskeletal remodeling and EMT, thereby promoting sustained proliferation, resistance to cell death and enhanced invasion. Importantly, context-dependent defects reveal that certain cancers exploit distinct translational vulnerabilities, for instance, MRPL11 downregulation in HNSCC shifts cells toward aerobic glycolysis, TUFM overexpression in colorectal adenoma-to-carcinoma progression correlates with poor prognosis, and mtEF4 knockdown in lung adenocarcinoma reroutes bioenergetics toward glycolysis. Preclinical evidence underscores the therapeutic promise of selectively targeting mitochondrial translation, tigecycline or anti-TUFM nanobodies curtail glioblastoma growth, GFM2 depletion attenuates PHGDH-driven hepatocarcinogenesis, and MRPS23 knockdown impairs HCC proliferation. These findings validate mitochondrial translation components as actionable vulnerabilities and position MRPs as prognostic biomarkers for patient stratification.

Looking forward, a deeper mechanistic understanding of how mitochondrial translation interfaces with oncogenic signaling, immune modulation, and therapy resistance remains a pressing need. Future studies should focus on delineating the context-specific roles of mitochondrial translation factors across diverse tumor types and stages. This could be achieved through multi-omics integration, high-resolution structural biology, and the development of in vivo models that faithfully recapitulate human mitochondrial dysfunction in cancer. Furthermore, prioritizing high-resolution mapping of mitoribosome factor interactions in diverse tumor contexts to uncover tumor-specific vulnerabilities and guide the design of high-affinity, cell-permeable inhibitors or degraders against key translation factors. Rigorous assessment of on-target mitochondrial toxicity and potential resistance mechanisms will be critical to advancing these agents toward clinical translation. Integrating mitochondrial translation profiling into genomic and proteomic pipelines can further refine predictive biomarkers, enabling personalized therapeutic approaches. Finally, dissecting compensatory signaling networks, such as AMPK/mTOR and BDNF/FAO axes, activated upon translational blockade will preempt adaptive resistance and inform rational combination regimens. By consolidating mechanistic insights and preclinical validations, this review provides a focused framework for advancing mitochondrial translation from a conceptual hallmark to a clinically actionable vulnerability in cancer therapy, thereby adding significant value to the scientific community’s efforts to develop targeted, metabolism-based treatments.